Modern way to distinguish executable files?

[Grzegorz Nosek]

Hi,

In ye olde nginx 0.5 I used the following to direct requests for 
executable files to fcgiwrap (for CGI support):

location / {
   root /some/where;

   # fastcgi setup
   if (-x $request_filename) {
     fastcgi_pass unix:/tmp/fcgiwrap.sock;
   }
}

What is the modern-day equivalent of this config (try_files and stuff)? 
I know I'll have to keep the if(-x) somewhere but I'm looking for a 
clean way to wrap it. I'd expect something like this but can't remember 
how to unconditionally direct requests to a named location:

location @upstream {
   # fastcgi setup
   fastcgi_pass unix:/tmp/fcgiwrap.sock;
}

location / {
   root /some/where;

   if (-x $request_filename) {
     # almost hurts to type this ;)
     try_files /nonexistent @upstream;
   }
}

All suggestions appreciated.

On a semi-related note, is the try_files config inherited in nested 
locations? i.e. will the following pass requests for /sub/uri to @upstream?

location / {
   location /sub {
     auth_basic "Hands off!";
     auth_basic_user_file /a/good/place;
   }

   try_files $uri $uri/ @upstream;
}

Best regards,
  Grzegorz Nosek